1. Field of the Invention
The present invention relates to a method and a circuit that facilitates identifying a remote end and optionally an intermediate location of an installed cable, such as a cable for carrying data, without the need to disconnect the cable and includes a circuit at one or more locations along the cable; the circuit including a power connector, a switching circuit and an indicator, such as a light emitting diode (LED), connected across a two wires in a cable for carrying data; the circuit being configured such that the indicator in each circuit is illuminated in response to a nominal voltage being applied to the power connector in any circuit connected to the two wires without disrupting any data being carried by the two wires in the cable.
2. Description of the Prior Art
The purpose of any networking cable is to carry data from one computer-related device to another. Computer-related devices include terminals, personal computers, printers, workstations, hubs, switches, storage devices, tape drives, and servers. Networking cables, frequently referred to as “jumper cables”, “jumpers”, or simply “cables”, typically are multiple pair copper wires packaged in an outer flexible sheath. Networking cables are designed to interconnect a computer-related device with another computer-related device. Such networking cables often are used in systems where there are many networking cables connected to frames or panels, each of which may have many connecting cables and which may be located closely adjacent other similar panels, sometimes without carefully regimented management of the cables. The connections of each cable may be remote from one another, even being in separate rooms or spaces, whereby the networking cables may be of substantial length.
One example of such use of networking cables is in computer centers where it is often necessary to connect a networking cable from an individual workstation at one location with another networking cable from a computer server remote from the workstation. Further the interconnections sometimes are located in crowded and/or cramped quarters. Tracing and identifying a remote connector section or end of a specific cable for changing its connection in a network or to facilitate replacement often is difficult, tedious and time consuming, and can lead to errors which create further service problems and additional costs.
Various methods and systems have been developed for locating the ends of a networking cable. One such method is a trial and error process that requires personnel to use test equipment at both ends of each and every wire pair to identify the termination points. This process may be labor intensive and expensive. The second method is a variation of the first method and involves the use of equipment to send a tone on a wire pair and then detect a particular frequency at the termination point. This process is also labor intensive. Also, to determine termination points, the cable needs to be disconnected from the computers connected to the network. As a result, these methods interfere with performance and require the workstation to be taken out of service. In addition, both systems require the test person to walk from one end of a test point to the other end. If the workstation and server are located in separate rooms or in remote locations, the previous methods are labor intensive and inefficient for easy detection of termination ends.
In the telecommunications context, U.S. Pat. No. 5,666,453 discloses a specialized fiber optic jumper cable for tracing remote connective portions of a fiber optic cable which includes a composite fiber cable, fiber optic connectors, electrically powered light emitting devices at the connectors, and a pair of electrical conductors embedded in the cable, with one or more electrical power connectors for selectively applying an external electrical power source to the light emitting devices. An LED and an electric power connector suitable for plug-in connection of a power pack are affixed to the cable adjacent each end such that both LEDs are lighted whenever power is applied to either of the electrical connectors. The attendant illumination of the LEDs provides an indication that the tracer system is activated and functioning properly and readily indicates where both ends of the same jumper cable are located. The electrical conductors also may be used for convenient telephonic communication by service personnel.
There is a need for an improved mode of readily tracing networking cables to easily and accurately identify a remote portion, and particularly to identify a remote end.